Performance Analysis of NOMA-Based Cooperative Spectrum Sharing in Hybrid Satellite-Terrestrial Networks

Xiaokai Zhang,Yan Ni,Bangning Zhang,Kang An,Daoxing Guo,Zhunyun Chen,Bing Zhao

doi:10.1109/access.2019.2956185

Abstract

In this paper, the performance of non-orthogonal multiple access (NOMA) based cooperative spectrum sharing in hybrid satellite-terrestrial networks (HSTNs) is investigated, where the primary satellite network recruits the secondary terrestrial network as a cooperative relay. To improve the fairness and spectrum utilization under cooperative spectrum sharing (i.e. overlay paradigm of cognitive radio), the NOMA power allocation profile is determined by instantaneous channel conditioning at the second temporal phase. The closed-form outage probability and approximated ergodic capacity expressions for the primary user (PU) and the secondary user (SU) are derived by decode-and-forward (DF) relay protocols, where the generalized Shadowed-Rician fading and Nakagami-m fading are considered for satellite links and terrestrial links, respectively. Simulation results are conducted for validation of the theoretical derivation and analysis of the impact of key parameters, and prove the superiority of NOMA comparing to conventional orthogonal multiple access (OMA) schemes on cooperative spectrum sharing in HSTNs. Besides, the fairness analysis between the PU and the SU is introduced by Jain's fairness index (JFI).

Highlights

SATELLITE communication (SATCOM) has earned a lot of attention in the field of navigation, broadcasting and multicasting services because of the huge coverage area [1]
First of all, we propose an overlay cooperative spectrum sharing scheme in hybrid satellite-terrestrial networks (HSTNs), where the secondary terrestrial network acts as a relay for primary satellite simultaneously and the transmission duration is divided into two temporal phases
SIMULATION RESULTS we apply the representative simulation to validate the theoretical results of the closed-form express on above and study the impact of some key parameters on the performance of cooperative spectrum sharing in HSTNs

Summary

INTRODUCTION

SATELLITE communication (SATCOM) has earned a lot of attention in the field of navigation, broadcasting and multicasting services because of the huge coverage area [1]. The work in [14] proposes a cooperative scheme to improve the wireless spectrum utilization and tackles unreliable satellite direct communication (DC) link, which can be seen as the overlay paradigm. Inspired by the above observations, a NOMA-based on cooperative spectrum sharing scheme in HSTNs is proposed to improve the spectrum utilization and tackle the fairness issue by decode-and-forward (DF) relay protocols for dynamic power allocation by instantaneous channel conditions. First of all, we propose an overlay cooperative spectrum sharing scheme in HSTNs, where the secondary terrestrial network acts as a relay for primary satellite simultaneously and the transmission duration is divided into two temporal phases. Considering the fairness of the overlay paradigm at the second temporal phase, the NOMA-based power allocation profile is determined by instantaneous channel conditions for both the PU and the SU.

CHANNEL MODELS

OUTAGE PROBABILITY

SIMULATION RESULTS

CONCLUSION